Nitrogen (N) fertilizer management is one of the important aspects of economic production of sorghums in sustainable agriculture. The aim of the study was to evaluate the effects of different N application rates and its split N application methods on productivity, growth characteristics, N accumulation, N use efficiency (NUE), and feed value of Sorghum × Sudangrass hybrids. Treatments consisted of five N application rates (0, 150, 200, 250, and 300 kg ha-1) and two split N application methods (40% in basal N, 30% at the growing stage, and 30% after the first harvest vs. 50% in basal N and 50% after the first harvest). Plant height, leaf width, and stem diameter were increased (p≤0.05) with increasing N fertility rates at each harvest. Chlorophyll content (expressed as SPAD values) was the highest at a rate of 300 kg N ha 1 (first harvest, 46.32; second harvest, 33.09). It was the lowest at zero N (first harvest, 21.56; second harvest, 18.5). Total N, N uptake, and NUE were increased with higher N rates. Split N application had little effect on total N, amount of N uptake, or NUE. Total dry matter yields were the highest (21,715 kg ha-1) at a rate of 300 kg N ha-1. It was the lowest (10,054 kg ha-1) at zero N. Our results suggest that more than 300 kg N ha-1 can improve dry matter yield to be above 116% compared to zero N, thus enhancing the agronomic characters of sorghums. However, no significant effect had been found for split N application. Further work is needed to determine the optimal N levels and the effect of split N application rates.

Background : The purpose of this study is to investigate the effect of split application and adapted fertilization application cultivation in stable medicinal herbs production of Angelica acutiloba K. And it accomplished one’s purpose to GAP guide manual established standard method of cultivation technology, contribute to the enlargement of farm’s income. Methods and Results : Method of fertilization application were conducted under four condition compose to standard application (N-P-K-Compost: fermented mixed oil cake fertilizer applied at 14-10-10-600 ㎏․10 a−1cultivation. Compost and fused phosphate applied at 100% of basal fertilizer in April 14. The split application level of standard application (N-K) applied at 100%, 50%, 40%, 30% of basal fertilizer in April 14, 50%, 40% and 30% of top dressing were two, three times application (N-K) in June 1, July 15, August 15, 25% and 20% respectively. Sowing dates with Jangsung varieties in April 28 of the year 2015. Planting density were spaced 30 ㎝ apart in rows 15 ㎝ apart with black color non-woven cloth covering open cultivation by level row 90 ㎝. Plot design randomized block 3 repetition. Conclusion : Growth characteristics by 50%, 70% and 60% of top dressing were two, three times application (N-K) in June 1, July 15, August 15 compared to standard application (N-K) applied at 100% basal fertilizer, aerial part as a result were so many such amount of growth as number of leaf per plant, etc., Length of leaf and main root of aboveground, subterranean part growth increment rising highest. Dried roots yields compared to standard fertilizer 100%application (217 kg․10 a−1) treatment. 50%, 70% and 60% of top dressing were two, three times application (N-K) increased by 6%, 14%, and 18%. respectively.

남부지방에서 황금재배시(黃芩栽培時) 적심시기(摘芯時期)와 질소, 가리의 추비방법에 의한 증수효과(增收效果)를 구명하고자 여천(麗川) 재래종(在來種)을 공시(供試)하여 재식거리(裁植距離)를 4×10cm로 4~5립(粒)을 4월 1일에 점파하였고 적심시기(摘芯時期)는 무적심구(無摘芯區)와 7월상순 1회 적심(摘芯), 7월상순과 8월중순에 2회 적심(摘恣)한 3처리에 대해 기비(基肥) : 추비(追肥) 비율(比率)을 70% : 30%, 60% : 20+20%, 50% : 20+20+20%으로 하여 시험을 수행한 결과를 요약(要約)하면 다음과 같다. 1. 토양의 화학성을 보면 시험후 토양이 시험전 토양에 비해 유기물(有機物), 유효린산(有效燐酸), 가리, 칼슘, 마그네슘, C. E. C 함량이 증가되는 경향을 보였다. 2. 적심시기(摘芯時期) 및 분시방법간(分施方法間)의 생육은 7월상순과 8월중순에 적심직후(摘芯直後) 2회 추비(追肥) 시용구가 무적심(無摘芯)의 7월상순 1회 추비(追肥) 시용구에 비하여 경장(莖長)들은 짧았으나 분지수(分枝數,) 경태(莖太등) 지상부와 주근장(主根長), 상근중(上根重) 비율(比率) 등 지하부 생장량이 증대되었다. 3. 건근수량(乾根收量)은 무적심(無摘芯) (158kg/10a)에 비해 2회 적심구(摘芯區)가 15% , 1회 적심구(摘芯區)가 10% 증수(增收)되었으며 질소, 가리 비료의 분시방법간(分施方法間)에는 2회 추비(追肥) 시용구가 1회 추비(追肥) 시용구 (150kg/10a)에 비해 상근중(上根重) 비율(比率) 향상으로 29% 증수(增收)를 보였다. 4. 2회 적심(摘芯) 처리에서 건근수량(乾根收量)은 경장(莖長)과 주당(株當) 생경엽중(生莖葉重), 지상부 생육간(生育間)에 질(負)의 상관(相關)이 인정되었고 주당(株當) 분지수(分枝數) 및 주근량(主根長)및 상근중(上根重) 비율(比率)과는 밀접한 정(正)의 상관(相關)을 보였으며 2회 추비(追肥) 시용재배에서도 경장(莖長), 주당분지수(株當分枝數) 및 주근량(主根長), 주근경(主根徑)등 지상, 지하부 생육과 건근수량간(乾根收量間)에 고도의 유의성이 인정되었다.